The subject matter herein relates generally to antenna assemblies, and more particularly, to antenna assemblies having multiple antenna elements with hemispherical coverage.
Wireless communication devices are in wide use today, particularly due to the convenience of enabling wireless access to applications and data. Wireless communication devices typically utilize antenna assemblies to establish a wireless connection with other devices. Typical wireless communication devices include computers, game consoles, cell phones, MP3 players, PDA's and the like, that are coupled to a network such as a wireless local area network (LAN). The LANs are used in the wireless transmission and reception of digitally-formatted data using transceivers operating at least one frequency range, such as 2.4-2.5 GHz., 5.2-5.8 GHz., and others. Antennas are required for the transceivers operating over these frequency bands. Typically, the antennas are designed to operate in a relatively narrow frequency range and thus have a limited bandwidth.
The vast majority of antennas are simple vertical rods a quarter of a wavelength long. Such antennas are simple in construction, usually inexpensive, and both radiate in and receive from all horizontal directions. One limitation of these antenna is that the antenna does not receive in the direction in which the rod points. Reception above and below the antenna is reduced in favor of better reception (and thus range) in other directions.
Prior art wireless communication devices have constantly strived toward improved performance while following the continuing trend toward lower cost, and ever more compact antenna designs. Known antennas are not without disadvantages. For instance, in wireless LAN data transfer operations, loss of signal strength, interruptions in data transfer, and the deleterious effects of signal interference all present potential sources of error and problems with known antennas during data transfer. These problems are exaggerated with antennas that operate in wider frequency ranges.
A need remains for an antenna that can be used in multiple frequency bands. A need remains for an antenna that provides good omnidirectional coverage.